JP6196960B2 - Pressure sensor - Google Patents

Description

  The present invention relates to a pressure sensor.

There is a pressure sensor that measures the pressure of a fluid to be measured flowing inside a pipe. Among these pressure sensors, there is a type in which a joint is connected to a connected member of a pipe, and a pin for opening a valve provided on the connected member is provided on the joint.
A conventional example of this type of pressure sensor includes a joint connected to a connected member, a pressure sensor element welded to the joint, and an operation member provided in the joint, and connects the joint to the connected member. In this case, there is a pressure sensor in which an operating member opens a valve provided in advance in a connected member (see, for example, Patent Document 1).
In Patent Document 1, the operation member is formed of a pin made of a stepped cylindrical member, and this pin is fixed to the joint by welding.

As another conventional example of this type of pressure sensor, there is a sensor in which a carrier is provided on one surface of a PCB (Printed Circuit Board), a pressure conversion member is provided on the other surface of the substrate, and the substrate is provided in a fitting. (For example, refer to Patent Document 2).
In Patent Document 2, since the carrier is fitted with a valve such as a Schrader valve, it functions as a pin in Patent Document 1 and is made of metal. The fitting functions as a joint in Patent Document 1.

Japanese Patent No. 4043874 US Pat. No. 7,377,177

However, in patent document 1, since the pin which is an operation member is being fixed to the joint by welding over the perimeter, it is considered that it is made of metal and the sealing property between the joint is secured by the welding. Yes. For example, a metal pin is formed by grinding a cylindrical member made of stainless steel by grinding or the like. However, the processing operation is complicated, which contributes to high cost of the pin.
In Patent Document 2, since a carrier corresponding to a pin is made of metal, there is a problem similar to that of Patent Document 1.

  The objective of this invention is providing the pressure sensor which can form an operation member easily.

The pressure sensor of the present invention includes a pressure sensor element that is displaced by the pressure of a fluid to be measured introduced through a member to be connected, and a pressure sensor element that is integrally joined to the pressure sensor element and introduces the pressure of the fluid to be measured into the pressure sensor element inside A metal adapter in which a hole for forming the hole is formed, a metal fitting member in which a housing recess for storing the adapter is formed and connected to the connected member, and a valve provided in the connected member And an operation member formed with a communication path that communicates the flow path into which the pressure of the fluid to be measured of the connected member is introduced and the hole of the adapter, and the adapter and the fitting member At least one of the surfaces that are in contact with each other in the direction orthogonal to the axial direction is plastically deformed, and biting occurs between the other and is hermetically joined, and Portions located in a direction that maintains a binding of axially eating write Mukoto to the other with the local plastic deformation and elastic deformation pressure, the operating member includes a contact portion that contacts with the adapter, the contact It is a synthetic resin member which has a pressing part which is provided on the opposite side to the part and presses the valve.

According to the present invention, for example, since the fitting member is plastically coupled to the adapter (metal flow), both are integrated, and the fluid to be measured does not leak from between them.
In the above configuration, the operation member is processed into a predetermined shape by injection molding or the like. Since the operation member is made of synthetic resin, it is easy to process. Therefore, mass production becomes possible and cost reduction can be achieved.

In the pressure sensor according to the present invention, the operation member has a flange portion that contacts the adapter, and a pin main body integrally formed with the flange portion, and a tip of the pin main body presses the valve. The fitting member includes a joint that is screwed to the connected member, and the joint has an operation member engagement hole into which the operation member is engaged, and is continuously formed in the storage recess. The member engagement hole preferably includes a large-diameter hole portion in which the flange portion is accommodated, and a small-diameter hole portion that is formed continuously with the large-diameter hole portion and through which the pin body passes.
According to the present invention, after the operation member is disposed in the operation member engagement hole, the adapter is stored in the storage recess, and the adapter and the fitting member are plastically deformed and coupled. Since the operation member is disposed between the fitting member and the adapter, the operation member is positioned by coupling the fitting member and the adapter. In addition, since the operation member engaging hole is formed by the large diameter hole portion and the small diameter hole portion, the operation member is prevented from coming off. Therefore, since it is not necessary to join the operation member directly to the fitting member by welding or the like, the assembly work of the pressure sensor is facilitated.

In the pressure sensor of the present invention, the pressure sensor element includes a diaphragm portion in which a strain gauge is formed, and a cylindrical portion that is coupled to an outer peripheral edge portion of the diaphragm portion and into which the pressure of the fluid to be measured is introduced. It is a metal member, It is preferable that the opening edge part of the said cylindrical part and the edge part of the said adapter are joined by welding.
According to the present invention, since the pressure sensor element and the adapter are integrated by welding, they can be easily attached to the fitting member.

  In the present invention, it is possible to provide a pressure sensor in which an operation member can be easily formed.

Sectional drawing which shows the pressure sensor which concerns on one Embodiment of this invention. The exploded perspective view of the pressure sensor.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
1 and 2, the pressure sensor 1 of the present embodiment is configured as a pressure sensor for measuring the pressure of a fluid to be measured used in, for example, an in-vehicle air conditioner, and an unillustrated pipe through which the fluid to be measured flows. It attaches to the to-be-connected member 2 such as a pipe-side joint provided in.

  Specifically, the pressure sensor 1 includes a pressure sensor element 10 that is displaced by the pressure of the fluid to be measured introduced through the connected member 2, and a pressure sensor element 10 that is integrally joined to the pressure sensor element 10 and contains the fluid to be measured in the pressure sensor element 10. A metal adapter 20 made of stainless steel or the like in which a hole 21 for introducing pressure is formed, and a storage recess 31 in which the adapter 20 is housed and formed in a metal such as aluminum or iron connected to the connected member 2 The fitting member 30 and the communication passage 41 that communicates the flow path 4 into which the pressure of the fluid to be measured of the connected member 2 is introduced by pressing the valve 3 provided on the connected member 2 and the hole 21 of the adapter 20. And the adapter 20 and the fitting member 30 are connected by plastic deformation. In addition, the code | symbol 5 in FIG. 1 is a coil spring which urges | biases the valve | bulb 3 to the operation member 40 side.

  In this case, the plastic deformation bonding is a bonding technique also called metal flow. That is, the fitting member 30 is plastically deformed at the inner peripheral surface that is in contact with the adapter 20 in the direction orthogonal to the axial direction, and bites between the adapter 20 and is hermetically joined. The portion that is positioned bites into the adapter 20 with local plastic deformation and elastic deformation pressure, and the axial elastic deformation pressure is sealed to maintain the axial coupling.

  The pressure sensor element 10 is a metal member such as stainless steel having a diaphragm portion 11 in which a strain gauge is formed and a cylindrical portion 12 that is coupled to the outer peripheral edge portion of the diaphragm portion 11 and into which the pressure of the fluid to be measured is introduced. It is.

  The adapter 20 has a pair of concave groove portions 22 that are provided at intervals along the communication direction of the hole portion 21 and that are recessed from the outer peripheral portion toward the inside in the radial direction. The concave groove portion 22 is provided continuously in the circumferential direction. By pressing the opening peripheral region A of the housing recess 31 in the fitting member 30 with a predetermined pressure, the inner peripheral surface of the housing recess 31 is plastically deformed and bites into the recessed groove portion 22 of the adapter 20, and the above-described plastic deformation coupling is performed. Is called. The end of the adapter 20 and the open end of the cylindrical portion 12 of the pressure sensor element 10 are all-around welded by, for example, laser welding.

  The fitting member 30 includes a cylindrical joint 32 that is screwed into the connected member 2. On the inner surface of the joint 32, a female screw portion 33 into which the male screw portion 6 of the connected member 2 is screwed is formed. On the outer peripheral portion of the end portion of the joint 32, an operation portion 32A that engages with a hand tool such as a hexagon wrench is provided. An operation member engagement hole 34 into which the operation member 40 is engaged is formed continuously to the storage recess 31 on the connection side with the connected member 2 with respect to the storage recess 31 in the fitting member 30.

  In the operation member engagement hole 34, a portion on the storage recess 31 side is a large diameter hole portion 35 in which a flange portion 44 described later of the operation member 40 is stored, and a portion on the connection side with the connected member 2 is large. The small-diameter hole portion 36 is formed continuously from the radial hole portion 35 and penetrates a pin body 45 described later of the operation member 40.

  The operation member 40 is a synthetic resin member such as PPS (Poly Phenylene Sulfide Resin), and is provided on the side opposite to the contact portion 42 that contacts the adapter 20 and the contact portion 42 and presses the valve 3. It has a pressing portion 43, a flange portion 44 that is integrally formed so as to be flush with the contact portion 42, and a pin body 45 that is integrally formed with the flange portion 44. The tip of the pin body 45 serves as the pressing portion 43 that presses the valve 3. The pin main body 45 is provided with a notch opening 45A that allows the communication passage 41 to communicate with the outside. The operation member 40 is interposed between the adapter 20 and the large-diameter hole portion 35 of the fitting member 30.

  In addition to the above components, the pressure sensor 1 is an annular insulating member (including a PCB or an arbitrary resin member) mounted on the fitting member 30 so as to surround the pressure sensor element 10 or a pressure provided on the insulating member. An output terminal for signal extraction conducted through a strain gauge and wire bonding of the sensor element 10 and a cover for covering these are provided. However, in FIG. 1 and FIG. 2, illustration of those components is omitted.

Below, the assembly procedure and operation | movement of the principal part of the pressure sensor 1 are demonstrated.
First, as shown in FIG. 2, the pressure sensor element 10 is engaged with the end of the adapter 20, and the engaging portion is welded by laser welding or the like over the entire circumference, so that they are integrated as a sensor module assembly. Thereafter, the operation member 40 and the sensor module assembly are inserted into the operation member engagement hole 34 and the housing recess 31 of the fitting member 30 in the order from the side opposite to the connection side with the connected member 2.

  As a result, the operation member 40 is engaged with the operation member engagement hole 34 and is interposed between the large-diameter hole portion 35 of the operation member engagement hole 34 and the adapter 20. Further, the pressure sensor element 10 is exposed from the housing recess 31 to the outside of the fitting member 30.

Next, a predetermined pressing force is applied to the opening peripheral region A of the storage recess 31 by a press machine or the like, and the adapter 20 and the fitting member 30 are coupled by plastic deformation bonding.
As described above, the assembly of the main part of the pressure sensor 1 in which the pressure sensor element 10, the adapter 20, and the operation member 40 are incorporated in the fitting member 30 is completed.

  When attaching such a pressure sensor 1 to the member 2 to be connected, when the joint 32 is screwed into the member 2 to be connected, the pressing portion 43 of the operating member 40 abuts on the tip of the valve 3 in the middle. The valve 3 is pushed back against the spring force of the coil spring 5. Then, the flow path 4 of the connected member 2 is opened, and the pressure of the fluid to be measured introduced from the flow path 4 acts on the pressure sensor element 10 through the notch opening 45A, the communication path 41, and the hole 21 of the operation member 40. . Then, an electrical output corresponding to the pressure is generated by a strain gauge and output to the outside via an output terminal (not shown).

According to this embodiment, there are the following effects.
(1) That is, in the pressure sensor 1, since the fitting member 30 is plastically coupled to the adapter 20, both are integrated, and the fluid to be measured does not leak from the coupling portion.
In the above configuration, the operation member 40 is processed into a predetermined shape by injection molding or the like. Since the operation member 40 is made of synthetic resin, it can be easily processed. Therefore, mass production becomes possible and cost reduction can be achieved.

(2) In the pressure sensor 1, after the operation member 40 is disposed in the operation member engagement hole 34, the adapter 20 is stored in the storage recess 31, and the adapter 20 and the fitting member 30 are plastically deformed and coupled. Accordingly, since the operation member 40 is disposed between the joint 32 and the adapter 20, the operation member 40 can be easily positioned by coupling the adapter 20 and the fitting member 30. In addition, since the operation member engagement hole 34 is formed by the large diameter hole portion 35 and the small diameter hole portion 36, it is possible to prevent the operation member 40 from coming out of the operation member engagement hole 34. Therefore, since it is not necessary to join the operation member 40 to the fitting member 30 directly by welding or the like, the assembly work of the pressure sensor 1 can be facilitated.

(3) In the pressure sensor 1, since the pressure sensor element 10 and the adapter 20 are integrated by welding, they can be easily attached to the fitting member 30.

(4) Since the adapter 20 and the fitting member 30 are continuously plastically deformed and joined in the circumferential direction to ensure sealing performance, there is no need to interpose a seal member such as an O-ring between them. The cost can be further reduced by reducing the number of points.

The present invention is not limited to the embodiment described above, and modifications, improvements, and the like within the scope that can achieve the object of the present invention are included in the present invention.
For example, in the above-described embodiment, the pressure sensor element 10 is an electric resistance type in which a strain gauge is formed in the diaphragm portion 11. However, the pressure sensor element used in the present invention changes according to the movement of the diaphragm portion. It may be a capacitance type that measures pressure from the capacitance to be used, or may be a so-called MEMS (Micro Electro Mechanical Systems) sensor manufactured by using a semiconductor microfabrication technique.

  In the above embodiment, the female screw portion 33 is formed on the fitting member 30 and the male screw portion 6 is formed on the connected member 2. However, the male screw portion is formed on the fitting member and the female screw portion is formed on the connected member. May be.

The metal material used for the fitting member and the adapter of the present invention is not limited to the materials described in the above embodiment, and is arbitrarily determined in consideration of compatibility in carrying out plastic deformation bonding and required mechanical strength. May be.
In carrying out the plastic deformation coupling, the surfaces which are in contact with each other in the axial direction may be plastically deformed on the adapter side depending on their shape and material, as well as on the fitting member side as in the above embodiment. May be.

  The present invention can be used as a pressure sensor for measuring various fluid pressures (including gas pressure, liquid pressure, and vapor pressure).

  DESCRIPTION OF SYMBOLS 1 ... Pressure sensor, 2 ... Connected member, 3 ... Valve, 4 ... Flow path, 10 ... Pressure sensor element, 11 ... Diaphragm part, 12 ... Cylindrical part, 20 ... Adapter, 21 ... Hole part, 30 ... Fitting member , 31, storage recess, 32, joint, 34, operation member engagement hole, 35, large diameter hole, 36, small diameter hole, 40, operation member, 41, communication path, 42, contact portion, 43, pressing Part 44 ... flange part 45 ... pin body.

Claims (3)

A pressure sensor element that is displaced by the pressure of the fluid to be measured introduced through the connected member, and a hole that is integrally joined to the pressure sensor element and that introduces the pressure of the fluid to be measured into the pressure sensor element are formed therein. A metal adapter formed, a metal fitting member formed with a housing recess for accommodating the adapter and connected to the connected member, and a valve provided on the connected member to press the connected member An operation member formed with a communication path that communicates the flow path into which the pressure of the fluid to be measured is introduced and the hole of the adapter,
At least one of the adapter and the fitting member is hermetically joined by plastic deformation of a surface that is in contact with the other in a direction orthogonal to the axial direction, and biting between the other and the circumferential direction. position portion in the maintaining binding of axially eating write Mukoto to the other with the local plastic deformation and elastic deformation pressure,
The operation member is a synthetic resin member having a contact portion that contacts the adapter and a pressing portion that is provided on the opposite side of the contact portion and presses the valve. . The pressure sensor according to claim 1,
The operating member has a flange portion that contacts the adapter, and a pin main body integrally formed with the flange portion, and a tip of the pin main body serves as the pressing portion that presses the valve,
The fitting member includes a joint screwed to the connected member;
In the joint, an operation member engagement hole with which the operation member is engaged is formed continuously with the storage recess,
The operation member engagement hole has a large-diameter hole portion in which the flange portion is accommodated, and a small-diameter hole portion that is formed continuously with the large-diameter hole portion and through which the pin main body passes. Pressure sensor. The pressure sensor according to claim 1 or 2,
The pressure sensor element is a metal member having a diaphragm portion in which a strain gauge is formed and a cylindrical portion that is coupled to an outer peripheral edge portion of the diaphragm portion and into which the pressure of the fluid to be measured is introduced. The pressure sensor, wherein the opening end of the cylindrical portion and the end of the adapter are joined by welding.

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